"Vis sit tecum" is latin for the familiar phrase "may the Force be with you." After taking latin for two years, this is close to all I remember. Many geeks will already possess this knowledge, as Star Wars is a major geek pillar, and latin is perhaps the geek language of choice.

You can pronounce this one of two ways. The correct way, as taught to me by my magister (and thus, perhaps subject to debate...), is to pronounce the "v's" as "w's", the "a" should be long, and the "c" should be hard. Wis sit tay-kum.

The most popular method for incorrecly pronouncing the phrase would be with a "vee-" sound at the beginning of "vis". This is how most people will pronounce "veni, vidi, vici", which will make a latin teacher reach for their sidearm.

Not that all latin teachers carry guns. Maybe just mine.